Signaling system and apparatus



March 19, 1940. v. w. LEONARD I 2,194,310

SIGNALING SYSTEM AND APPARATUS Original Filed Aug. 8, 1935 5 Sheets-Sheet 1 Inventor:

.\/incent W Leonard.

J ifi Attorngg.

March 19, 1940. v, w, LEONARD 2,194,310

SIGNALING SYSTEM AND APPARATUS Original Filed Aug. 8, 1935 3 Sheets-Sheet 2 In ventov: Vincent Leonard,

56 9457721 7 Man is AGt orngg.

March 19, 1940. v. w. LEONARD smmune SYSTEM AND APPARATUS Original Filed Aug. 8, 1935 3 Sheets-Sheet 3 mi \w:

In ventcm: Vincent Leonard,

Hi5 Attorn e Patented Mar. 19, 1940 UNITED STATES SIGNALING SYSTEM AND APPARATUS Vincent W. Leonard, Saugus, Mass assignor to General Electric Company, a corporation of New York Application August 8, 1935, Serial No. 35,316

REISSUED NOV 3 6 1940 Renewed December 13, 1939 14 Claims.

My invention relates to signaling systems and apparatus and more particularly to signal systems and controllers for controlling street traflic.

One object of my invention is to provide an im- 5 proved system of control wherein the operating relationship between controllers can be changed from a central control point in such manner that only a predetermined signal at each intersection will be affected during the change period.

Another object of my invention is to provide an improved signal controller which may be adjusted from a central control point to operate a series of signals on any one of a plurality of predetermined time schedules.

Another object of my invention is to provide an improved system of tra'flic signal control whereby from a central point a series of controllers may be simultaneously controlled to operate their respective trafllc signals on any one of a plurality of different time schedules and in predetermined operating relationships to each other.

Another object of my invention is to provide an improved control dial whereby the relationship between the controllers and the signal periods at each controller may be easily adjusted.

For a better understanding of my invention, together with other and further objects thereof, reference is had to the following description, taken in connection with the accompanying drawings, and its scope will be pointed out in the appended claims.

Referring to the drawings, Fig. 1 illustrates a front view of an improved controller built in accordance with my invention. The cover of this controller is partially broken away to give a clear view of the dials and contacts controlled thereby; Fig. 2 is a detail view of the dials shown in Fig. 1; Fig. 3 is an end view of the dial of Fig. 2 shown partially in section; Fig. 4 is an exploded view, partly diagrammatic, of the controller of Fig. l; and Fig. 5 is a diagram of connections illustrating the connection between the elements of the controller and the method of adjusting the controller from a central control station.

Referring to the drawings in detail, Figs. 1 and 4 illustrate a traflic signal controller Ill provided with three dials ll, l2, and I3, each of which represents a separately adjustable schedule of operation for that controller. The dials are mounted in front of a panelboard l4 and are normally protected by a cover l5 hinged to the panel I4 and provided with windows IS. The dials are respectively mounted on and rotated by shafts a gear 23 mounted on a common drive shaft 24. y it The gears 20, 2 I, and 22 are all provided with the same number of teeth so that the three dials are driven at the same speed by the shaft 24.

The common drive shaft 24 is driven by a motor 25, preferably a self-starting synchronous motor, through a clutch 26 and speed changing gears 21. The clutch 26 comprises a pair of co-operating members 28 and 29. Member 28 is loosely mounted on a shaft 30 and is driven by the motor 25 through a worm gear 3| and worm wheel 32. The member 29 is keyed to the shaft 39 by a pin 33 and slot 34.. This member is moved in and out of engagement with member 28 by a forked lever 35 pivoted at36. An armature 31 is attached to the forked lever 35. This armature is attracted by a core 38 when a coil 39 mounted thereon is energized. When the armature is attracted, it moves the member-29 out of engagement with member 28 against the force of a spring 40 to open the clutch and thereby stop the controller.

The clutch shaft 30 operates an idler shaft 4| of the speed changing device through a pair of bevel gears 42 and 43, shaft 44 and spur gears 45 and 46. The idler shaft 4| carries a set of interacting idler gears 41, 49, and 49, the first of which is keyed to shaft 4|, and the third, being connected to the first through the second gear, engages a nest of gears 59 mounted on a shaft 5|. The gears 48 and 49 are mounted on an arm 52 which is pivoted on the idler shaft 4| and may be moved about its pivot so as to engage or disengage idler gear 49 with the gear nest 50. The

means of moving the arm 52 about its pivot is a forked lever arm 53 and a bar 54 mounted on a frame 55. The frame 55 is attached to the core 56 of a magnet coil 51 through bar 58. For the purpose of changing gears, shaft 4| is moved, carrying with it the idler gears 41, 43, and 49. The driving gear 46 remains stationary, axially, the shaft 4| being slidable through its hub. At each movement of the shaft 4| the coil 51 is energized to move the gears out of engagement with the gear nest. In order to hold the idlers in proper engagement with the gear nest at each driving position of the idlers, the bar 54 and frame 55, being stationary in a horizontal direction, are! inclined from the horizontal. At each movement of the idler shaft, the forked arm 53 slides along the bar, thereby adjusting the position of the idler 49 to engage the gears 50. The speed changer shaft 5| is connected to the common dial drive shaft 24 by bevel gears 59. v

The idler shaft 4| is moved axially by a ratchet mechanism comprising a pair of oppositely arranged ratchet wheels 88 and 8| mounted on a shaft 88 and a pair of ratchet pawls 88 and 88 for moving the wheels 88 and 8I respectively inopposite directions. A star wheel 88 mounted on the shaft 82 and a pin 88 urged into the notches on the star wheel by a spring 81 holds the shaft 88 in any position until either pawl 88 or 88 operated by coils 88 and 88 respectively move the-shaft to the next notch on the star wheel. An indicator dial 18 mounted on the shaft 82 in front of the panel I8 indicates the gear ratio setting. A gear 1| attached to the other end of the shaft 88 engages a rack 18 attached to the idler shaft H and moves the idler gears into engagement with the proper gear in the gear nest.

The dials II, I8, and I8 are provided with keys, such as 18, 18, and 18, which operate contacts of control switches mounted on the panel I8 in such manner that certain circuits are closed by each key as it passes the sets of contacts. These circuits cause the operation of the tramc signals through a signal switch comprising a drum contrailer 18. The keys in each of the three dials are spaced in accordance with a different predetermined schedule, or time cycle. The keys on only one of the three dials-operate the drum c'ontroller at any one time, the operating dial being selected by a dial selector 11. This selector holds the controller to the selected schedule, or cycle, until a predetermined signal of the sequence is energized; then causes a change to a newly selected dial and schedule, or cycle, providing a different schedule has been selected at the central control station. The details of the signal operation and selector mechanism can be explained more readily by reference to Fig. 5.

In Fig. 5, I have illustrated conductors 18, 18, 88, ll, 88, and 88. which comprise the connecting cable between several intersection controllers, such as illustrated in Fig. 4, and a central control station which may be at any convenient location. This central control station includes a double-throw switch 88, comprising the schedule selector control switch; push button switches 88 and 88 comprising the speed changing switches, and a supervisory timer 81. The supervisory timer 81 may be and is preferably one of the intersection controllers. It includes a cam 88 and a switch 88 operated thereby. The switch is normally closed and connects common conductor 18 to ground through conductor 88 and contacts 8I--88. The supervisory cam 88 is operated at a predetermined speed equal to the normal speed of the gear shaft St in each intersection controller. Each shaft 8| is provided with a cam 88, corresponding to the cam 88, and a switch 88. The switch 88 is normally open and is closed momentarily once during each signaling cycle. when the switch 88 does close, it. energizes the clutch coil 88 through a circuit which may be traced from common conductor 88, the power feed conductor. conductors 88 and 88, switch 88, conductor 81, clutch coil 88, conductors 88, the synchronizing conductor 18, conductor 88. supervisory switch 88 to ground. The function of the two cams 88 and 88 is to open and close the circuit to clutch coil 88. When the intersection controller cam 88 reaches the switch 88, it closes the switch and thereby establishes a feed circuit through the supervisory switch 88 to the clutch coil 88 which then functions to declutch the timer. If at the same instant the cam 88 functions to open switch 88, the circuit to the clutch coil remains broken and the timer continues to operate. This, therefore. is the method of placing the timers in synchronism with the supervisory timer and therefore with each other.

The three dials II, I8, and I8 each comprise a graduated core which is rigidly attached to the drive shaft, and an adjustable dial assembly which carries the keys. When the controller is assembled the keys 18, which I may term the zero keys, are set directly above the zero graduations, or marks, on the cores. The contacts for each dial are then set so that they will be simultaneously operated by the keys 18, and cam 88 is set to close contacts 88 at this instant. This adjustment is then a reference point from which each adJustment is made when the controller is put into operation. If the controller is used as a supervisory controller as above mentioned, the cam 88 is changed to a contact opening cam 88 as illustrated. This original setting of the cams with respect to the dial cores and contacts is never changed, but the zero keys may be advanced on successive controllers to obtain the necessary time interval betwen successive green periods on a main thoroughfare. This type of control is commonly referred to as "progressive control since the signals change as the vehicles progress from one intersection to the next. It may be noted here that due to the assembly and subsequent adjustments just described, the synchronization between successive controllers does not necessarily take place during the main street green period. Under normal circumstances, however, this synchronizing circuit operates only once when the controllers are first started. After that the motors, running synchronously, keep the controllers in synchronism and the cams 88 and 88 merely operate to check this condition.

The push buttons 88 and 88 operate to increase or decrease the gear ratio at the timers. Button 88, when depressed, establishes a circuit from the power conductor 88 to coil 88 through conductors 88, I88, 82 and III. The coil 88 isconnected in series with coil 81 by conductor I88 and to ground. Every time button 88 is depressed, this circuit is established and coil 88 raises pawl 88 to advance the wheel 88, shaft 88, gear 1I and rack 18. The idler gears are thereby moved toward the high speed end of the gear nest. The coil 81 being simultaneously energized disengages the idler 88 and allows it to re-engage in the new position. When button 88 is depressed, a circuit is established to coil 88 through conductors 88, I88, 8| and I88. Coil 88 is also connected in series with coil 81 and to ground. Coil 88 operates pawl 88 and wheel 8I, thereby moving the idler gears toward the low speed end of the gear nest.

As stated above, only one dial at a time controls the traffic signals. It is, therefore, assumed, for the sake of convenience, that dial I8 is connected to control the traillc signals. Dial I8 is provided with the three keys I8, 18, and 18. Key 18 is permanently placed in one of the peripheral slots I88 and is used as a reference key and commonly referred to as the zero key because it is usually used to mark the beginning of the green or go" signal for the main street. A key 18 is placed in another one of the slots I88 along the periphery and marks the end of the green main street period. Other keys 18 are inserted atpredetermined points in the periphery of the dial. Only one of these keys is illustrated for the sake of simplicity. The actual number of the keys 18 in each dial is dependent upon several factors which will appear in the following description.

Adjacent the path of movement of the dial keys, two pairs of spring mounted contacts are placed side by side. Thus, contacts I08 and I01 constitute one pair of contacts that are normally separated. The upper contact I01 is provided with a finger I08, which when engaged by any one of the keys, lowers the contact I01 to engage contact I06 to establish a circuit. Next to the contacts I06 and I01 is a second pair of contacts I09 and H0, contact IIO being provided with a finger I I I, which when engaged by key 14,- lowers the contact IIO into engagement with contact I09 to establish a circuit. It is to be noted that key 14 is longer than the keys 13 and 15. As a result thereof, the key 14 operates both pairs of contacts simultaneously, while keys 13 and 15 operate only the first pair of contacts. When the first set of contacts I06 and I01 are closed by a key, a circuit is established to a drum operating coil I I2. This circuit may be traced from the common cable conductor 83 through conductor II3 to the coil H2 and through conductor II4 to switch II5. This switch being closed,

, current flows to conductor II6, switch arm II1 of the selector switch 11, contact II8, conductor II9, switch arm I20, contact I2I, conductor I22, contacts I06 and I01 to ground. When coil I I2 is thus energized, it lifts its core I23 and pawl I24. The latter engages a ratchet wheel I 25 and turns the controller one notch. This operation is repeated at each closure of switch I06-I01 until a cam 5' opens the switch II5. In that case, the closure of the contacts I06-I01 does not energize the coil II2, but a closure of both sets of contacts establishes the circuit. This may be traced as follows: Conductors 83 and II3, coil H2, conductor I I4, switch arm I26, contact I21, conductor I28, switch arm I29, contact I30, conductor I3I, contacts I08, IIO, conductor I22 and contacts I06 and I01 to ground. The contacts I09 and H0, therefore, shunt the open switch II5 to establish the circuit to coil I I2. This is the means for synchronizing the drum controller with the dial. The long key 14 which brings about this resynchronization is usually placed at the end of the green period for the main street and cam H5 is set to open switch H5 in the main street green position of the drum controller so that if the drum controller should be out of step with the dial, the delay required for resynchronization will occur only during the main street green period.

The actuating mechanism for the drum controller 18, as stated, comprises the coil I I 2, which, when energized, lifts its core I23 and pawl I24. It also closes a locking circuit in shunt to the switch I I5 by means of a switch I32. This switch is closed at each actuation of the core and establishes a circuit from conductors II4 to H6 through its contacts and conductor 6'. The purposeof this is to insure that the circuit to coil II2 shall remain closed until broken by contacts I06I01, that is, the circuit should not be prematurely broken at switch contacts II5 before the pawl I24 has completed its stroke. The drum controller comprises a series of cams for operating switches which in turn open and close, in a predetermined sequence, the circuits to a set of traffic signals I34. The signals are illustrated in a conventional diagrammatic manner comprising two groups of three signals each, designated by the letters M" for main street and C for cross street. Each group contains the conventional R" signal for the stop" indication, A for the caution" indication and G" for the go indication. A group of cams I35 to I40 arranged on a cam shaft I operate respectively a series of switches I42 to I41 for energizing the signals. In Fig. 5, switches I43 and I48 are illustrated as being closed whereby the G" signal for the main street and the R. signal for the cross street are energized. The circuits may be traced from conductor I I3, switch I43, conductor I48, signal "G" main and common conductor I49 to ground. The other circuit may be traced from conductor II3, switch I48, conductor I50, signal 3" cross to ground. In the same manner, switch I41, when closed, energizes the R. main 'signal through conductor I6I; switch I45 controls A" main through conductor I52; switch I 44 controls "G" cross through conductor I53 and switch I42 controls "A cross, through conductor I54.

The operating mechanism for the drum contrailer is shown in somewhat greater detail in Fig. 4. In this figure, the coil armature I23 is connected to a pivoted cam I51, on one end of which the pawl I24 is mounted by means of a pin I56. A second pawl I58 co-operating with a ratchet wheel I59 is arranged to prevent a movement of the drum beyond its predetermined position. When the coil II2 draws in its armature I23, the cam surface at the opposite end of the cam I51 drops the pawl I58 into a notch in wheel I59 by releasing a pin I60. The drum meanwhile moves one full position until the pawl I58 reaches the end of the notch and stops further movement of the drum. When the coil is de-energized and pawl I24 returns to engage the succeeding notch, the drum is held stationary by a third pawl I33 which engages the ratchet wheel I25 while pawl I58 is lifted out of the notch in the wheel I59 and is held in position to enter the next notch when the coil is again energized.

The selection of the dial, as already stated, is accomplished by a selector switch 11 remotely controlled from the central control station by switch 84. In Fig. 5, the switch 84 is shown in its mid position, in which it is open circuited and the switch 11 is thereby in its normal position wherein dial I3 determines the schedule of signal operation as above described. Assuming now that switch 84 is thrown to engage the right-hand contact I6I, a circuit is established from the power conductor 83, through switch 84, contact I6I, conductor I62, conductors 19 and I63, coil I64 to ground. The coil I64 operates the switch arms H1 and I26 by means of an armature I65 and connecting link I66. It must be noted, however, that the switch arms cannot be moved until released by an interlocking mechanism comprising an interlocking fork I61 having arms I68 and I69, an armature I10 and an actuating coil I1I. When the coil I1I is deenergized, the arm I68 engages a pin I12 and thereby prevents the energized coil from moving the switch arms H1 and I26 to the new position. The same condition exists when the central control switch 84 is thrown to the left to engage a contact I13. In that case, a circuit is established from the power conductor 83 through the switch arm 84, contact I13, conductors I14, and I15, coil I16 to ground. The coil then attempts to move switch arms I20 and I29 to a second position by means of an armature I11 and link I18. This is prevented, however, by arm I69 of the fork I61 and by a pin I19 attached to the switch mechanism.

It is, therefore, possible to throw the central control switch 84 and energize either of the actuating coils of the switch, but on change of connections will take place until the coil I10 lifts the (ill interlocking arms and permits the switch arms to take up their respective new positions. This is accomplished by a cam I88 mounted on shaft 5| and'a switch I8I. The cam maintains the switch in open position, but closes it momentarily once each signaling cycle. This moment is chosen to be in such relation to the green main period on the dials and signal drum that the switch I8I is closedduring that period. When switch I8I is closed, it establishes a circuit to coil I18 of the interlock from the power conductor 88, conductor 85, switch I8I, conductor I82, coil I18 and to ground. When the coil I18 is energized, it withdraws both arms I88 and I88. In accordance with the set-up of the switch 88, however, only one of the coils I88 and I18 can be energized at a time and only one of the two pairs of switch arms are moved when the interlock is removed.

Assuming again the switch 88 thrown to the right to engage contact I8I and the interlock. being removed, the switch arms H1 and I28 will be moved to establish a circuit to a set 01' contacts operated by dial I2. The switch arm I28 will engage a contact I88, thereby establishing through a conductor I88 a. circuit to a pair of contacts I88 and I88 similar to the contacts I88-II8. Switch arm II1 establishes a circuit to a second pair of contacts I81-I88 through a conductor I88. Contact I88 is grounded and contacts I88 and I 81' are connected together through the conductor I 88. The contacts operated by the dial I2 then advance the drum 18 as already described for dial I8.

When the central control switch 88 is thrown to the left to engage contact I13, coil I18 is energized and when the interlock operates, the coil moves the switch arms I28 and I28 to a new position. In the new position, switch arm I28 engages a contact I88 and establishes through a conductor I8I a circuit to a pair of contacts I82-I83 similar to contacts I88--I8'I. Switch arm I28 establishes a circuit through contact I88, conductor I85 to a pair of contacts I88-I81 similar to the contacts I88II8. The pairs of contacts I 82l 88 and I88I 81 are adjacent the dial II. The circuit to the drum operating coil II 2 may be traced from switch arm I28 to conductor II8, contact II 8, switch arm I I1 and conductor I I8; also from contact arm I28 to conductor I28, contact I21, contact arm I28 and to conductor H8. The circuit through the coil II2 is completed from conductors H8 and "8 as previously explained. The switch arms H1 and I28 are in contact with the lower contacts H8 and I21 because coil I88 was de-energized when the switch 88 was thrown to the left. It may be noted here that when either coil I88 or I18 is de-energized by the central control switch 88 being moved to its central or open position from either contact I8I or I18, the forked member I81 being in its lower position prevents the contact arms from changing position. In other words, the latch or forked member I81 locks the contacts into the second position as well as the first position until the release coil "I is energized as above explained. By means of the central control switch 88, therefore, the respective dial and contacts may be selected, but the changeover from one dial to the next is not accomplished until the interlock operates. It is an easy matter to obtain the operation of the interlock at any desired point in the operating cycle by adjusting the cam I88. It is found, however, that the most desirable place is during the right-of-way period on the main street or highway, since any prolongation at this period delays the least trafllc possible.

In accordance with another phase 01' my invention, I have devised an improved dial for obtaining the desired adjustments in the abovedescribed controller. Referring. specifically to Figs. 2 and 3, I have illustrated, in detail, a dial built in accordance with my invention and comprising a dial core I88 which is graduated and provided with a serrated edge having serrations corresponding to the graduations on the dial core. The core I88 is mounted on a hollow shalt I88. which in turn revolves on a pin 288 rigidly attached to the panel I8. Adjacent the core I88 and pressed against it by a spring 2" is dial 282 which covers the core I88 and is provided with a window 288 through which the graduations on the dial core I88 are visible. The dial 282 is loosely mounted on a sleeve 288 which is attached to the core I88 and supports the spring 28I. A collar 288 mounted on the end of the sleeve 288 holds the spring 28I under compression.

The dial 282 is provided with a series of closed slots I88 large enough to accommodate the keys 18, 18, and 18, and has attached thereto a series of rings 288 and 281 by means of rivets 288. The ring281 is of the same outside diameter as the dial 282 and is provided with a series oi! slots I88 corresponding to those in the dial and located opposite the slots I88 in the dial. Two rings 288 are used and spaced from each other from the dial 282 and ring 281 respectively by suitable spacers. The outside diameters of the rings 288 is such that they extend to approximately'the center line of the slots in the dial. Open-ended slots are placed in the periphery, their depth being equal to the slots on the dial, and they are placed opposite to the slots I88 in the dial and slots I88 in the ring, so that the keys may project through from the dial 282 to and through the ring 281.

In the space formed between the dial 282, ring 281 and the reduced diameter oi. the rings 288, a helical spring 288 is placed under tension. When a key is inserted through the slots of the dial 282 and the rings 288 and 281, it must necessarily displace one or more of the turns of this spring and is thereby held in the dial. In order to facilitate the spring holding the keys in place, the keys are provided with notches 2" into which the helices of the spring are forced.

The dial assembly comprising the dial 282, rings 288, 281, together with the spring 288 and the keys, is normally locked to the core by a locking lever 2II projecting through the dial 282 and provided with a knife-edge 2I2 for enga ng the serrations on the periphery of the dial core I88. The lever 2 is pivoted on a bracket 2I8 attached to the back of the ring 281 and is forced into the serrations by a spring 2. By merely lifting this lever 2, the dial assembly is released from the core and may be rotated with respect to the core I 88. As stated above, the serrations correspondent to the graduations on the core so that the dial may be moved to any one of the graduations desired. A pointer in the window 288 and the numbered graduations on the core are a guide to the relative displacement of the controller dials with respect to one another and with respect to the corresponding dials on other controllers in the system. The entire dial, including the core driving gear and hollow shalt, may be removed from the pin 288 by removing iii) the screw H6 and washer 2|! and at the end of the pin.

Having above described the structure of my controller, the operation thereof in a control system may be explained by reference to the drawings and several minor details that have not yet been explained. Before the several controllers are installed, the timing of the signals is at each intersection determined graphically. By actual trafiic count, for example, it may be determined what division of right of way at each intersection will create the least congestion. This division of the right of way is sometimes referred to as percentage split". It has been found in some instances that mornings the greatest flow of trafllc is into the city; at night, out of the city; and during the day, the traffic division is approximately an average between the two. The dials are, therefore, marked In, Out and Average, to indicate these three conditions and the keys are spaced in the peripheral slots so as to proportion the time between the stop and go periods of the intersecting streets for these conditions. The zero key 13 being used as a reference, the key is placed directly above the pointer in the dial window 203 and the dial is set so that this key is over the graduation of the core.

The next step is to determine the time necessary for a vehicle to travel between successive intersections at the maximum allowed speed and accordingly set the dials with respect to the dial cores. For this purpose, the first controller dial is left at zero and the corresponding disk of each succeeding controller is set several divisions subsequent to that setting in order to obtain a progression of the beginnings of the green periods. This is done for each dial separately.

When the controllers are installed and the power is turned on, they all start with the dial settings just described, but will stop as soon as the synchronizing cam 93 opens the clutch. The controllers will thus individually stop their respective signals until the supervisory cam 88 breaks the clutch circuit and restarts the con- .trollers in step with each other.

The drum operating ratchet wheel and the operating impulses in each controller are so chosen that the drum will make one complete step-by-step revolution every time the dial completes a revolution. For this reason, the total number of keys in each dial must correspond to the number of teeth in the ratchet wheel I25. The cams on the controller drum are so arranged that they will operate the signals through a complete cycle in one full revolution of the drum shaft. In Fig. 5, .I have illustrated six teeth on the ratchet wheel i25 necessitating six keys in each of the dials. It must be borne in mind that the number of impulses may be greater than the number of signal combinations. It is, for example, practicable to have a greater number of teeth than the normal number of signal com binations so that additional signal combinations can be arranged subsequent to the installation of the controller. In the present illustration, the signal combinations are G main R cross. GA main R cross, R main G cross, and R main GA cross, making four combinations. Dial I3 controls the signals in the illustration. The controller assumed the G main and R cross signals when key 13 passed finger Hi8 in a counterclockwise direction. The following impulse occasioned by a key 15 will advance the drum one notch and will cause the opening of the interlock switch 5. A

change in the signal combinations does not take place at this time, the drum cams being arranged to continue the existing signal combination for this period. The next impulse is occasioned by key 14, which shunts the interlock switch H and thereby advances the drum to change the signals to GA main and R cross. If the dial and drum are out of step at this impulse so that one of the short keys passes the contacts, the drum does not advance because the circuit to the drum operating coil I I2 is open at switch H5.

'Key 14 being the only long key is the only key in each dial capable of closing the shunt circuit to the switch H5. In the present example, key 14 closes the contacts l09ll0 to advance the drum. In the case of dial I2, the key M closes the contacts I 85-!86, and in the case of dial H,

,it closes the contacts |96--|91. The next impulse is occasioned by another key 15 and changes the signals to R main and G cross. This signal is held through the next impulse and changed by the followingimpulse to R main GA cross. The key I3 then returns the signals to the first combination. It is, therefore, evident that there are two impulses which are held in reserve to obtain other signal combinations by changing the cam set-up on the drum should they be desired.

The time that it takes a dial to make a revolution determines the length of a signal cycle. This time canbe regulated from the central control station by means of the push buttons. If a longer cycle should be desired, push button 86 is pressed, and if a shorter cycle should be desired, the push button 85 is closed. At each closure of the respective buttons, the cycle is increased or decreased by a predetermined increment.

The dial selector switch is operated at different times of the day and is ordinarily operated to select the In dial mornings, the Out dial evenings, and is placed in the de-energized position during other periods of the day whereby the Average dial I3 operates the signals. It may be pointed out here that the change from one set of dials in the system to another set simultaneously effects the progression of traiilc along the main street and the percentage split at each intersection. The positioning of the zero keys with respect to the cores determines progression, and the positioning of the keys l4 and 15 with respect to the zero key determines the percentage split.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a trafllc-signal system, the combination of a group of traflic signals, a drum switch operable step by step to energize said trafllc signals in a predetermined sequence, a plurality of dials having keys mounted therein, means for simultaneously driving said dials, means for operating said drum switch step by step in accordance with the spacing of said keys in each dial respectively, and means for effecting operation of said operating means through any one of said dials and its respective keys at a time to operate said drum switch.

2. In a signal system, a plurality of controllers, a corresponding series of signals connected to each of said controllers respectively, means in each controller for operating the signals connected to it at one of a plurality of predetermined time schedules, means in each controller for simultaneously effecting operation of the signals connected to it at one of said predetermined time schedules, and means for preventing operation of said signal operating means at said selected schedule in each controller until a predetermined signal is energized by said controller.

3. In a signal system, the combination of a plurality of control switches, a single set of signals, means for operating said signals in a predetermined sequence and at time intervals controlled by said switches respectively, a dial for operating each switch at a predetermined time schedule, a selector switch forconnecting the switch controlled by any one of said dials to said signal operating means, and means for preventing the operation of said selector switch until a predetermined one of said signals is energized.

4. In a signal system, the combination of a plurality of control switches, a set of signals, means for operating said signals in a predeter mined sequence connected to be controlled by said switches respectively, a selector switch connected between said control switches and said signals for connecting any one of said control switches to control said signals, and interlocking means attached to said'selector switch for preventing the operation of the said selector switch until a predetermined signal is energized.

5. In a signal controller, the combination of a plurality of control switches, means for actuating said switches at any one of a plurality of predetermined schedules, a signal switch, means responsive to each actuation of any one of said control switches respectively to advance said signal switch, a selector switch operable to connect any one of said control switches to said signal switch advancing means, and interlocking means for preventing a change of said control switch connections until said signal switch is in a predetermined position.

6. In a trafllc-signal system, the combination of trafllc signals and circuits therefor for a main and an intersecting street, a drum switch operable to energize said signals in predetermined combinations, means for operating said drum switch step by step including a plurality of control switches, an actuating dial for each of said control switches operable to control said signals at predetermined time schedules respectively, a selector switch connected between said control switches and said drum operating means operable to connect said control switches so as to effect the control of said signals by one dial at a time, and interlocking means for preventing an operation of said selector switch until the right of way for said main street is indicated by said signals.

7. In a signal controller, the combination of a signal circuit switch operable to energize predetermined signal combinations successively, means for operating said signal switch in accordance with any one of a plurality of predetermined time schedules including a plurality of control switches and adjustable actuating means for said control switches respectively, a selector switch operable to connect any one of said control switches to control said signal switch including remote controlled actuating means for said selector switch and an interlock normally preventing an operation of said selector switch, and means operated by said control switch actuating means for releasing said interlock when a predetermined signal combination is energized.

8. In a traillc signal control system, the combination of a series of controllers, each controller including a signal switch operable to energize predetermined signal circuit combinations successively, means for operating said switch at any one of a plurality of time schedules and means for efl'ecting an operation of said switch operating means at any one of said schedules including a selector switch provided with movable contacts, operating magnets for moving said contacts, and interlocks for normally preventing a moving of said contacts, central station control means for simultaneously energizing a predetermined one of the operating magnets in each selector switch, and means within each controller respectively for operating said interlock to release the contacts of said selector switch when the signal switch in said controller has energized a predetermined signal combination.

9. In a signal system, the combination or a plurality of control switches, a set of signals, means for operating said signals in a predetermined sequence connected to be controlled by said switches respectively, a selector switch connected between said control switches and said signals for connecting any one oi. said control switches to control said signals, and interlocking means associated with said selector 'switch for preventing the operation of said selector switch until a predetermined signal is energized.

10. In a signal controller, the combination 01 a signal switch operable to energize predetermined signal circuit combinations successively, means ior operating said signal switch in accordance with any one of a plurality of predetermined time schedules including a plurality of control switches and adjustable actuating means for said control switches respectively, a selector switch operable to connect any one of said control switches to control said signal switch including a remote controlled actuating means for said selector switch and an interlock normally preventing an operation of said selector switch, and means for releasing said interlock when a predetermined signal combination is energized.

11. In a trafllc signal control system, the combination of a plurality of controllers each of said controllers including a signal switch operable to energize predetermined signal circuit combinations successively, means for operating said switch at any one of a plurality'of time schedules, and means for effecting a change in the operation of said switch operating means from any one of said schedules to another of said schedules comprising a selector switch provided with movable contacts, operating magnets for moving said contacts, and interlocks for normally preventing a movement of said contacts, means for operating said interlocks to release the contacts of said selector switch when the signal switch has energized a predetermined signal combination, and central station control means for simultaneously energizing a predetermined one of the operating magnets in each selector switch of said plurality of controllers in the system.

12. In a tramc signal controller, the combination of a plurality of primary dials provided with adjustable switch actuating members, a stationary switch associated with each primary dial and arranged to be actuated by the actuating members of that dial, a secondary dial associated with each primary dial, driving means for driving said secondary dials in a fixed relation relatively to each other, and locking means for locking each primary dial in any one of a predetermined number of positions relatively to its associated secondary dial, whereby all the switch actuating members of a dial may be moved simultaneously relatively to the switch actuating members of the other primary dials in the controller.

13. In a trafilc controller, the combination of a rotatable shaft, a plurality of secondary dials, shafts for driving said dials respectively, means for driving said secondary dials in a predetermined fixed relationship relatively to each other and to said shaft, primary dials associated with said secondary dials respectively, locking means operable to lock said primary dials in any desired angular relationship to its respective secondary dial, keys in said dials and switching means associated with each dial respectively and mounted in a fixed position relatively to each, of said dials respectively whereby said switches may be operated in any desired relationship dependent upon the adjustment of said primary dials relatively to said secondary dials.

14. In a trafiic signal controller the combination of a rotatable shaft, a plurality of secondary shafts, means for driving said secondary shafts in a fixed relationship from said drive shaft, secondary dials attached to each of said secondary shafts respectively, primary dials mounted upon each of said secondary shafts respectively, and rotatable relatively to said sec-' ondary dials respectively, said primary dials being provided with peripheral slots, keys mounted in predetermined ones of said slots in each primary dial, switch members mounted in fixed and operative relationship to the keys in each of said primary dials respectively, and means for locking each primary dial in any one of a plurality of positions relatively to its secondary dial whereby the switch members are operated in a relationship determined by the relative adjustments of said primary dials relatively to their respective secondary dials.

VINCENT W. LEONARD. 

